Finer points of Wordpress

$wpdb
get_template_part
wp_post_revisions
hooks
SVN
is_plugin_active
esc_url()
wp_debug in wp-config.php
register_taxonomy()
wp_localize_script();
$wpdb->query()
is_user_logged_in
post_per_page
get_post_meta
get_footer()
the_content
the_title()
$wpdb->get_var($query)